Mercury arc rectifier



Dec. 29, 1931. R H A R 1,839,069

MERCURY ARC RECTIFIER Filed Dec. 5, 1929 Inve ncor: Frank P. Whitaker,

His Attorney Patented Dec.- 29, 1931 UNITED. STATES PATENT orFic FRANK r. WHITAKER, or RUGBY, ENoLANn-Assrcmon "110 GENERAL rm, A conromrron or NEW YORK ntncrmc com- MERCURY ARC anemia-Inn Application filed December 5, 1929, Serial no. 411,926, and in Great Britain December- 10,1928. V

This invention relates to mercury arc rectifiers, and more particularly to anode lead-in constructions for use in such apparatus.

It is well known that a vacuum tight seal between the anode stem and the anode insulator can be made by a packing of asbestos or similar material, sealed with mercury.

With such constructions there is the disadvantage that if the seal leaks the sealing mercury runs down on to the anode itself Where its presence may produce back-firing of the rectifier.

The object of this invention is to construct an anode lead-in such that if the mercury leaks from the seal the quantity appearing at any time at. the anode surface will not be deleterious. h 7

According to the invention a chamber preferably of annular form is provided immedi-.

ately below the asbestos packing of the seal.

If mercury leaks through the seal it will be able to collect in this chamber, andv thus not directly reach the anode surface. The chamber is preferably located so as to be kept cool by the cooling medium provided for the anode stem, and thus such evaporation of the mercury in the chamber as takes place will be slow, and not deleterious.

Further, the chamber for receiving the leakage of mercury may be provided with a drain plug, so that when the anode assembly has been adjusted to be vacuum tight any initial mercury which has leaked in can be drained away. After draining away this mercury the drain plug is replaced.

' The accompanying drawing illustrates diae grammatically a typical form of theinVen tion.

In the diagram, 1 is the hollow tubular,

anode stem, which is closed at its bottom end by a plug 2. Theanode stem may be kept walls of the vacuum chamber of the rectifier,

and by which the anode is insulated from the latter. The insulator 4 is carried by and sealed vacuum tight to the wallsof the vacu' um chamber-"at 5, the details of the construe at 6, and covering this with mercury 7, thus providing a vacuum tight seal. Any convenient means, not illustrated, may be used for keeping the asbestos tight, and for retaining the mercury.

Below the seal the'insulator is provided internally with alipl8, bearing on the rim of a member 9 secured to the bottom end of the anode stem. Member 9 is so formed as to provide an annular chamber 10 into which any mercury leaking in from the seal can drip and collect, this chamber being kept cool by the cooling medium inside. The lip 8 of the insulator is pressed against 9 by thewasher 11, clamp ring 12, and screws 13.

A drain screw 14 is provided by means of which when the anode tip is removed, any

mercury which has collected-in the chamber;

10 can be drained out.

The anode tip bears against the bottom .end' of the anode insulator by a flexible gasket escape slowly through the gasket 15, which however fits too tightly for the arc to be able to get to the anode stem or member 9 at the back of the anode tip.

What I claim as new and desire to secure 'by Letters Patent ofthe United States, is: coolin any convenient way such as by filling 1. An anode lead-in construction for mercury arc rectifiers and the like including an anode stem, an anode insulator, a mercury seal interposed therebetween, and a cooled chamber arranged to collect any sealing mercury that leaks through said seal and to per.- mits itsslow evaporation into the interior of the rectifier.

2. An anode lead-in construction according to claim 1, in which a drain plug is provided for draining out mercury which leaks in from the seal during its initial period of a dj ustment.

3. An anode lead-in construction according to claim 1 in which a flexible gasket is provided between the skirt of the anode insulator and the anode tip.

4;. An anode lead-in construction for mercury arc rectifiers and the like including an anode stem, an anode insulator, a -mercury seal interposed therebetween, and a cooled chamber closed at the bottom and having an annular Wall portion, said chamber being arranged to collect any sealing mercury that leaks through said seal and topermit its slow evaporation over the rim of said Wall intothe interior of the rectifier.

In Witness whereof I have hereunto set my hand this 12th day of November, 1929. V

FRANK P. WHITAKER. 

